That is how much time remained until the doors opened to the public when the final butterfly was placed on its pedestal and the external monitor was unplugged from the hidden Mac Mini.

360 seconds. I said to Chandler, the person responsible for getting the mechanical butterflies responding to Arduino issued commands, “That is cutting it kinda close dont you think.” His response was classic Barbarian.

“What are you talking about? What we have here is an example of near perfect timing.”

So that is how the Biomimetic Butterflies came to be. It started as a vague thread from many months ago, went through some revisions, was nearly abandoned, was revitalized, was expanded, and with 6 minutes to spare, was installed at the the McLeod Residence located in Seattle. It was the Barbarians second foray into the world of gallery installation which dont directly involve any client input. The first, McLeod Mirror Series 1: See Yourself in Others, was completed and installed a couple months back.

The butterflies were a result of a cross country collaboration between Barbarians located in San Francisco, Boston, New York, and Los Angeles. The pedestals were constructed by Vince, a fabricator in Seattle.

To make the butterflies, we starting tossing about different ideas for generative wing design. First up was Voronoi, which I discussed in the previous post. The Voronoi was decided upon because the vein structure of butterflies resembles Voronoi cells. This algorithm was stretched into two solutions, Angular Voronoi and B-spline Voronoi. The angular version had thin straight Voronoi boundaries and the B-spline version had curves fitted to the negative spaces created from the angular version.

Angular Voronoi

B-spline Voronoi

Next up was flow lines. I dont really understand the inner workings of this one, but it is essentially a fluid simulation that shows the direction of the fluid movement not as a grid of vectors but as a solid curved line. Its much more complex than it looks, that much I can tell you. This algorithm was also stretched into two versions. The second version mapped circles along the curved lines.

Flowlines

Circle Flowlines

Intersecting lines was probably the easiest to work out. Several lines are thrown into the butterfly wing outline and several can share the same intersection point. These points are augmented with a larger circular shape. The end result was surprising and extremely delicate once laser cut because only the lines were left behind and the solid negative spaces were cut away.

Intersecting Lines

Cracking! This one is also a bit foreign to me. I think the general rule for this piece was to take the wing shape and find its centroid. From here, several line segments would be drawn. The resulting shapes were also analyzed to find their centroids. This was repeated for several iterations and the retrofitted with B-spline curves.

Cracking

And finally, Circle Packing. Randomly sized created circles are randomly placed into the butterfly wing shape. If there is any overlap, that circle is tossed. This is run for a few thousand generations and the result is quite satisfying to see, especially the laser cut paper version.

Circle Packing

We then took these seven algorithms and created several prints, each print containing two butterflies from the same family. We also had one set of wings from each family laser cut into heavy stock paper. The individual butterfly wings were then attached to each other with thin fabric strips that would work as a hinge. The wings also had tiny spaces cleared away of laser cuts so tiny rare earth magnets could be sandwiched onto the paper.

The pedestals were hollow so they could accomodate stepper motors and much larger rare-earth magnets. The stepper motor could be controlled via Processing and Arduino so that it could rotate the large magnet up towards the top of the pedestal. The polarity of the magnets on the butterfly was such that the large magnet could push the smaller magnets away. Since the butterfly wings were pinned to the pedestal, they would take on the appearance of flapping.

I have to say, the result is a bit creepy. Its plainly obvious that they are not real butterflies. The body, head and legs were nowhere to be seen. You could even see the texture of the paper. And yet, they stirred some strange emotion that made one think these paper butterflies wanted to be free and were strugging against the black metal pins which held them in place. The silence of the mechanisms assisted in this illusion because no mechanical noise can be heard.

To assist in this illusion, a webcam was placed at the back of the room. It would look for movement in front of the pedestals and tell the corresponding butterfly to react. This means that if you were to walk into the room, you would see a bunch of butterfly prints and pinned butterflies in pedestals. As you walk closer to get a better view, the butterfly in the pedestal you approach would begin to flap its delicate wings.

For version 2.0, we are going to have more variety, faster wing movement, and smoother gradient between wings up and wings down. Fun!

View the quicktime video here.

Or watch the vimeo version below.

Biomimetic Butterflies from flight404 and Vimeo.

This entry was posted on Monday, July 9th, 2007 at 12:24 am and is filed under Processing. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.